When I visit the eye doctor, she tells me my vision is 20-20. However, when I look at a resistor, all I see is a rainbow smudge. I like the ohmmeter method!
Medium One has confirmed that cloud driven GPIO is not suitable for applications that require tight timing like PWM or implementing I2C. There is too much latency and uncertainty in the internet. Something pulsing multiple times per second would probably eat through our free cloud credit allocation very quickly. PWM would require a low level driver that handles the actual pulsing. It could be controlled or set by a cloud driven command.
I'm trying to brainstorm applications where we could use this capability. I like your alarm idea.